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G. S. GATCHELL.

LOOPER THREAD CONTROLLING MECHANISM FOR SEWING'MACHINES.

APPLICATION FILED NOV. 2h1918.

Patented Oct. 21, 1919.

3 SHEETS-SHEET I.

WITNESSES.

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LOOPER THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

' APPLICATION FILED NQV- 2!.1918. 1 ,EIQA'YW Patented Oct. 21,1919.

3 SHEETS-SHEET 2- WITNESSES.

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G. S. GATCHELL.

LOOPER THREAD-CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED NOVI 21,1918

Patented Oct. 21, 1919.

3 SHEETSSHEET 3- WJTNESSES.

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GEORGE S. GATGHELL, OF ROSELLE PARK, NEW JERSEY, A'SSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

LOOPER-TI-TREAD-CONTROLLING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Oct. 21, 1919.

Original application filed August 10, 1917, Serial No. 185,446. Divided and this application filed November To all whom it may concern:

Be it known that I, GEDRGE S. GAT'CHELL, a citizen of the United States, residing at Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Looper- Thread-Controlling Mechanisms for SewingMachines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to multiple needle sewing machines of the chain-stitch type disclosed in the patent to George E. Molyneux & George S. Gatchell, No. 1,266,036, of May 14, 1918, and has for an object to overcome in a large measure the objectionable defects caused by the inertia and stretching tendency of the looper-thrcad as it is being rapidly and alternately paid out and taken up during the advance and retreat of the looper. Further objects of the invention will appear from the following description and claims.

The present improvement is preferably embodied in the four-needle single-looper machine disclosed in my copending application Serial No. 185,446, filed August 10, 1917, of which this application is a division. The feature of novelty in the present case is the compact arrangement of a continuously rotating looper-thread controlling cam within the hollow work-supporting arm of the machine for the purpose of closely controlling the looper-thread at all periods of the cycle of operations at a point nearer the looper than has heretofore been considered feasible in machines of the present yp In the accompanying drawings,Figure 1 is a side elevation, partly in section, of a machine embodying the invention. Fig. 2 is a reverse side elevation of the machine. Fig. 3 is a horizontal section through the standard of the machine showing the workarm in plan. Figs. 4: and 5 are cross sec tional views through the work-arm taken on the lines l4 and 55, respectively, Fig. 3. .Fig. 6 is a detail perspective view of an element of the loo'per-actuating mechanism.

In the preferred embodiment of the invention, as illustrated, the machine frame is formed with a base 1 from which rises the standard 2 carrying the overhanging bracket-arm 3 terminating in the hollow Serial No. 263,452.

head 1. Secured'to the standard 2 is the flanged rearward extremity of the tubular work-supporting arm 5 which is formed with two angularly arranged flat sides 6, 7, (Figs. 4 and 5) and a curved upper side 8, whereby said work-arm is substantially sector-shaped in cross-section. Secured to the front or free end of the work-arm casting is the throat-plate 9 and the end cap 10. Jour naled in and crosswise of the standard 2, above the horizontal plane of the work-arm and crosswise of the vertical plane of the work-arm, is the main-shaft 11 carrying a driving pulley-wheel 12.

The main-shaft is formed with a ballcrank 13 which is embraced by the lower strapped end of a pitman 14 the upper strapped end of which embraces a ballended crank-pin 15 carried by the crank arm 16 at the rear end of the needle-actuating rock-shaft 17 which is journaled within the bracket-arm 3 and, at its forward end, carries a crank-arm 18 connected to the reciprocating needle-bar 19 by means of the link 20. Secured to the lower end of the needle-bar 19 are the needles, one of which is shown at 21.

Mounted within the end cap 10 in coiiperative relation with the needles, is the thread-carrying looper 22. The looper is secured to the looper-support 23 by a screw 24. The looper-support is clamped to the front end of the oscillating and endwise movable looper-shaft 25 which is journaled within and lengthwise of the work-arm 5 as closely as practicable to the apex of the angle formed by the flat sides 6 and 7 thereof, Figs. 4 and 5, said angle being large enough to accommodate the necessary loop-seizing and shedding strokes of the looper.

The looper-shaft 25 carries at its rearward end a crank-arm 26 having a ball-crank-pin 27 which is embraced by the lower strapped end of a pitman 28 the upper strapped end of which embraces a ball-eccentric 29 on the main-shaft 11 which imparts loop-seizing and shedding movements to the looper. The hub of the crank-arm 26 is formed with a rearward extension carrying a ball-ended pin 30 disposed concentrically with the axis of the looper-shaft and embraced by the socketed end of a link 31 whose opposite end is connected to the depending arm 32 of a rock-lever fulcrumed to oscillate upon and independently of the cross-shaft 33 journaled in the standard 2. The upwardly extending arm 34 of saidrock-lever is slotted at 35 to receive an adjustable pin 36 which,

through the pitman 37 connects said lever,

with the eccentric 38 carried by the mainshaft; said eccentric serving to impart sidewise or needle-avoiding movements to the looper.

The feeding mechanism comprises fulling and main feed-dogs, 39 and 40, repectively, actuated by suitable mechanism extending within and longitudinally of the work-supporting arm as more fully described in my said copending application.

Journaled within and crosswise of the rearward end of the work-arm 5 is'a shaft 41 which is connected to the gear 42 on the hollow counter-shaft 43 by a gear 44 of onehalf the size of the gear 42 in order that the shaft 43 will be driven at the same speed as the main-shaft 11, with which the gear 42 is connected bymeshing with a gear 45 of the same size as the gear 44 and fixed to the main-shaft; Mounted upon the shaft 41 and within the work-arm 5 is a looperthread controller-cam 46, a looper-thread pull-off cam 47 and a thread-niliwper actuating cam 48; the cams 46 and 47 being disposed on opposite sides of the looper-shaft 25 and operating in planes parallel with said shaft, as shown in Fig. 3.

The cam 46 comprises two similar spaced disks shaped to closely control the slack in the looper-thread as the looper advances and retreats, while the pull-off cam 47 also con prising'two spaced disks, is shaped to meas ure off a supply of looper-thread required for the formation of a stitch. Cotiperating with the cams 46 and 47 are thread-engaging forks 48 whose tines are apertured at 49 and whose shanks 50 are pivoted at 51 to brackets 52 mounted on lugs 53 within the work-arm. The thread-guiding apertures 49 may be raised or lowered by means of adjusting screws 53 and the rearward inclined ends of the shanks 50 are acted upon by springs 54 to yieldingly maintain the screws 53 in contact with the brackets 52 while permitting the forks to be swungupwardly to threading position. Suitable stripper wires 55 are situated between the disks of each cam. The nipper-cam 4S acts upon a pair of superposed nipper-springs 56 to nip the looper-thread; the timing in the present instance being such that the nippers are closed upon the thread as the looper begins its retracting stroke, and are opened as soon as the advancing looper has entered all of the needle-loops. The pull-off cam 47 begins to pull looper-thread from the supply as soon as the nippers 56 are closed without necessitating undue enlargement of the work-supporting arm.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, in combination, 'a frame comprising a main casing and a hollow work-supportingarm free at one end and at its opposite end joining the main framework of the machine, stitch-forming mechanism incorporated in'said frame'and including a threadcarrying looper operating at the free end of said work: supporting arm, a continuously rotating shaft journaled within and transversely of said arm, and a looper-thread controlling cam carried by said shaft and operating to closely and accurately control the looper-thread'at all pe riods of the stitch-forming cycle.

2. In a sewing machine, in combination, a frame comprising a standard, a hollow work-supporting arm free atone end and at its opposite end joining said standard above the base of the latter, whereby a clear space around the arm is provided to'permit the sewing up of tubular work, stitch-forming mechanism incorporated in said frame and including a thread-carrying looper operating at the free end of said work-supportin arm, an oscillatory and endwise movable shaft journaled within and lengthwise of the work-supporting arm and connections driven by said shaft for imparting loopseizing and needle-avoiding movements to said looper, and continuously rotating looper-thread take-up and pull-off cams mounted within the ivork-supporting arm on opposite sides of said looper-actuating shaftand operating in planes substantially Oopiu of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

a Washington, 1'0." 7 V a 

